The present invention relates to an apparatus for applying at least one coating of solution of a predetermined viscosity to a photosensitive material, as well as a cleaning and recirculation arrangement for the coating apparatus.
A coating apparatus as described in, for example, U.S. Pat. No. 5,984,539 generally applies a solution of a predetermined viscosity to photosensitive material, preferably processed photosensitive material, to form a protective overcoat on at least one surface of the photosensitive material. In order to apply a protective coating to an emulsion surface of a photosensitive material, control of the thickness, uniformity and laydown amount of the coating being applied is needed in order to apply for adequate protection against at least moisture. The control is needed for several reasons: 1) the protective coating must be applied in a manner that assures that the surface is uniformly coated, so that the coating can provide adequate protection to the entire surface; 2) the thickness of the coating must be controlled because if the coating is too thick, it could cause cracking, due to non-uniform drying; 3) a thick coating could dull the surface and underlying image of the photographic print; and 4) the coating solutions can be of different viscosities.
Generally, a coating apparatus as disclosed in, for example, U.S. application Ser. No. 08/082,957 filed May 21, 1998, which discloses one type of coating apparatus, utilizes an applicator roller for applying a solution of predetermined viscosity to the surface of photosensitive material. The solution is to be applied in a manner that provides for an even thickness of solution on the photosensitive material. These coating solutions tend to be such that over a period of time they can harden within the coating apparatus. If components, such as the rollers, of the coating apparatus become dirty with excess coating solution, they can leave artifacts on the photosensitive material. The cleaning of these components affects the efficiency of the coating apparatus by increasing the down time of the apparatus. Therefore, it is advantageous to provide for a coating apparatus that is capable of applying an even coating on the photosensitive material, and which further includes a mechanism for quickly and efficiently cleaning the components of the coating apparatus.
The present invention provides for a novel apparatus and method that can apply a solution of a predetermined viscosity to at least one surface of photosensitive material, preferably processed photosensitive material, prior to the final drying of the photosensitive material, to form a protective overcoat. In the present invention, the solution can be uniformly applied to the surface of the photosensitive material at a specific thickness.
The present invention further provides for a cleaning arrangement, which is capable of maintaining the components of the coating apparatus clean, so as to minimize any artifacts on the photosensitive material.
The present invention further provides for a recirculation system which is capable of alternately supplying coating solution and/or cleaning solution to the coating apparatus in an efficient manner, so as to minimize down time of the coating apparatus during a cleaning operation.
The present invention provides for a coating apparatus for applying a coating solution to photosensitive material. The coating apparatus comprises a support structure; first and second rollers mounted on the support structure so as to form a nip therebetween for the passage of photosensitive material therethrough; a tray position relative to one of the first and second rollers such that the one roller partially extends into the tray; and a wall having a blade extending therefrom. The blade extends to a surface of the one roller, while the wall and blade are positioned in the tray so as to divide the tray into a first section and a second section. The first section receiving coating solution therein such that the one roller is at last partially submerged in the coating solution. The second section defines a spillover basin that catches coating solution that spills over the blade from the first section.
The present invention further provides for a cleaning assembly for cleaning a coating apparatus, in which the coating apparatus has at least one application roller at least partially positioned within a solution tray of the coating apparatus. The cleaning assembly comprises a washing arrangement positioned relative to the application roller to supply cleaning solution onto at least the application roller; and a recirculation system that delivers cleaning solution to the washing arrangement and the solution tray.
The present invention further provides for a method of coating photosensitive material with a coating solution. The method comprises the steps of locating an application roller at least partially within a solution tray of a coating apparatus; supplying a coating solution to the solution tray such that the application roller is partially submerged in the coating solution; metering the coating solution on the application roller with a metering blade, as the application roller is rotated while at least being partially submerged in the coating solution; and passing a photosensitive material through a nip between the application roller and a drive roller. The nip is downstream of the metering blade with respect to a direction of rotation of the application roller, such that the coating solution is applied to a surface of the photosensitive material as the photosensitive material passes through the nip.
The present invention further provides for a method of cleaning a coating apparatus, in which the coating apparatus has an application roller at least partially positioned within a solution tray of the coating apparatus. The method comprises the steps of positioning a washing arrangement relative to the application roller so as to supply cleaning solution through the washing apparatus onto at least a surface of the application roller; and supplying cleaning solution to the washing arrangement and the solution tray.
The present invention further provides for a coating apparatus for applying a coating solution to at least one surface of the photosensitive material. The coating apparatus comprises a support structure; an application roller mounted to the support structure; and a tray located relative to the application roller so that the application roller at least partially extends into the tray. The apparatus further comprises a wall positioned with respect to the tray so as to divide the tray into first and second sections. One of the first and second sections is adapted to receive a coating solution therein, with the application roller being partially submerged in the coating solution. The other one of the first and second sections defines a spillover basin to catch coating solution that spills over from the one section.
The present invention further provides for a processing system that comprises a processor for processing photosensitive material; and a coating apparatus for applying at least one coating solution onto a surface of the processed photosensitive material. The coating apparatus comprises a support structure; an application roller mounted to the support structure; a tray positioned relative to the application roller such that the application roller extends into the tray; and a wall having a blade extending therefrom. The blade extending to a surface of the application roller, and the wall is positioned in the tray so as to divide the tray into a first section and a second section. The first section holds one of a coating solution or a cleaning solution supplied thereto so that the application roller is partially submerged into the one solution. The second section defines a spill-over basin to catch solution from the first section which spills over the metering blade.
The present invention further provides for an apparatus for coating at least one surface of a photosensitive material with a coating solution. The apparatus comprises an application roller adapted to apply coating solution onto a surface of photosensitive material; a first holding area for solution located relative to the application roller, so that the application roller extends at least partially therein and the application roller is at least partially submerged in solution in the first holding area. The solution is applied to the application roller at the first holding area. The apparatus further comprises a second holding area for solution positioned relative to the first holding area so as to catch excess solution that spills over from the first holding area.